How the us government works

Except in this scenario there is no way to just order both pepperoni and cheese pizzas. Say for example its a vote on whether to legalize gay marriage, or legalize marijuana, or to ban guns. If 55% vote yes (cheese) and 45% vote no (pepperoni) you can't just say "well, we'll just split the country in half and these guys will have it and those guys wont have it"

Actually on most bills if 55% voted one way (cheese) it would pass the senate. A bill needs to pass both the house and the senate, however, so yes in this case if some of your friends (senate) wanted cheese and some of your friends (house) wanted pepperoni then the bill would fail. (And even if the bill passed the president could still veto it). You know why it works like this? The constitution establishes a system of checks and balances. If a group with malicious intent seizes one house and tried to pass bills that are detrimental to the nation as a whole then they couldn't pass it if the other part of congress isn't controlled by that group. Our legislative branch is designed to be slow and inefficient so it lessens the threat of the government becoming tyrannical.